Quality control for intravascular intrauterine transfusion using cumulative sum (CUSUM) analysis for the monitoring of individual performance

Design of a Phase 3, Global, Multicenter, Randomized, Placebo-Controlled, Double-Blind Study of Nipocalimab in Pregnancies at Risk for Severe Hemolytic Disease of the Fetus and Newborn

OBJECTIVE

 Nipocalimab is a neonatal fragment crystallizable (Fc) receptor (FcRn)-blocking monoclonal antibody that inhibits placental immunoglobulin G (IgG) transfer and lowers circulating maternal IgG levels. In an open-label, single-arm, phase 2 study, nipocalimab demonstrated evidence of safety and efficacy that support further investigation in a pivotal phase 3 trial of recurrent hemolytic disease of the fetus and newborn (HDFN). The phase 3 AZALEA study aims to evaluate the efficacy and safety of nipocalimab in a larger population at risk for severe HDFN, defined as HDFN associated with poor fetal outcomes or neonatal death.

STUDY DESIGN

 AZALEA is a multicenter, randomized, placebo-controlled, double-blind, phase 3 study enrolling alloimmunized pregnant individuals (N ≈ 120) at risk for severe HDFN based on obstetric history. Participants are randomized 2:1 to receive intravenous 45 mg/kg nipocalimab or placebo weekly from 13-16 to 35 weeks gestational age (GA). During the double-blind treatment period, participants receive standard-of-care weekly monitoring for fetal anemia until planned delivery at 37 to 38 weeks of GA. Postnatal follow-up periods are 24 weeks for maternal participants and 104 weeks for neonates/infants.

RESULTS

 The primary endpoint is the proportion of pregnancies that do not result in intrauterine transfusion (IUT), hydrops fetalis, or fetal loss/neonatal death from all causes. Key secondary endpoints include the severity of HDFN as measured by a composite HDFN severity index, the earliest time to occurrence of IUT or hydrops fetalis, the modified neonatal mortality and morbidity index in liveborn neonates, and the number of IUTs received. Other endpoints are safety, patient- and caregiver-reported outcomes, pharmacokinetics, pharmacodynamics (e.g., IgG, FcRn receptor occupancy), and immunogenicity of nipocalimab.

CONCLUSION

 AZALEA, the first placebo-controlled, randomized, multicenter, prospective trial in severe HDFN, is designed to evaluate the safety and efficacy of nipocalimab, a potential preventive and noninvasive intervention, in at-risk HDFN pregnancies.

KEY POINTS

· Severe HDFN leads to poor fetal/neonatal outcomes.. · IUTs are associated with complications and fetal loss.. · Nipocalimab blocks IgG recycling and placental transfer.. · Nipocalimab reduces fetal anemia and IUTs in early-onset severe HDFN.. · The phase 3 AZALEA study evaluates nipocalimab in severe HDFN..

Management of Red Cell Alloimmunization in Pregnancy

Rhesus immune globulin has resulted in a marked decrease in the prevalence of RhD alloimmunization in pregnancy; however, antibody formation to other red cell antigens continues to occur. Evaluation for the presence of anti-red cell antibodies should be routinely undertaken at the first prenatal visit. If anti-red cell antibodies are detected, consideration of a consultation or referral to a maternal-fetal medicine specialist with experience in the monitoring and treatment of these patients is warranted. Cell-free DNA can be used to determine fetal red cell antigen status to determine whether the pregnancy is at risk of complications from the red cell antibodies. First-time sensitized pregnancies are followed up with serial maternal titers, and, when indicated, serial Doppler assessment of the peak systolic velocity in the middle cerebral artery should be initiated by 16 weeks of gestation. When there is a history of an affected fetus or neonate, maternal titers are less predictive of fetal risk; if the fetus is antigen positive, serial peak systolic velocity in the middle cerebral artery measurements should be initiated by 15 weeks of gestation because intraperitoneal intrauterine blood transfusions can be used at this gestation if needed. The mainstay of fetal therapy involves intrauterine transfusion through ultrasound-directed puncture of the umbilical cord with the direct intravascular injection of red cells. A perinatal survival rate exceeding 95% can be expected at experienced centers. Neonatal phototherapy and "top-up" transfusions attributable to suppressed reticulocytosis often are still required for therapy after delivery.

Organ-specific learning curves of sonographers performing first-trimester anatomical screening and impact of score-based evaluation on ultrasound image quality

INTRODUCTION

First-trimester anatomical screening (FTAS) by ultrasound has been introduced in many countries as screening for aneuploidies, but also as early screening for fetal structural abnormalities. While a lot of emphasis has been put on the detection rates of FTAS, little is known about the performance of quality control programs and the sonographers' learning curve for FTAS. The aims of the study were to evaluate the performance of a score-based quality control system for the FTAS and to assess the learning curves of sonographers by evaluating the images of the anatomical planes that were part of the FTAS protocol.

METHODS

Between 2012-2015, pregnant women opting for the combined test in the North-Netherlands were also invited to participate in a prospective cohort study extending the ultrasound investigation to include a first-trimester ultrasound performed according to a protocol. All anatomical planes included in the protocol were documented by pictures stored for each examination in logbooks. The logbooks of six sonographers were independently assessed by two fetal medicine experts. For each sonographer, logbooks of examination 25-50-75 and 100 plus four additional randomly selected logbooks were scored for correct visualization of 12 organ-system planes. A plane specific score of at least 70% was considered sufficient. The intra-class correlation coefficient (ICC), was used to measure inter-assessor agreement for the cut-off scores. Organ-specific learning curves were defined by single-cumulative sum (CUSUM) analysis.

RESULTS

Sixty-four logbooks were assessed. Mean duration of the scan was 22 ± 6 minutes and mean gestational age was 12+6 weeks. In total 57% of the logbooks graded as sufficient. Most sufficient scores were obtained for the fetal skull (88%) and brain (70%), while the lowest scores were for the face (29%) and spine (38%). Five sonographers showed a learning curve for the skull and the stomach, four for the brain and limbs, three for the bladder and kidneys, two for the diaphragm and abdominal wall and one for the heart and spine and none for the face and neck.

CONCLUSION

Learning curves for FTAS differ per organ system and per sonographer. Although score-based evaluation can validly assess image quality, more dynamic approaches may better reflect clinical performance.

Practice patterns amongst fetal centers performing intrauterine transfusions (PACT): An international survey study

OBJECTIVES

Fetal anemia secondary to incompatibility between maternal-fetal blood types can result in hydrops and demise. Intrauterine transfusions have improved survival in experience centers. Our objective was to determine the practice patterns amongst fetal centers.

STUDY DESIGN

Thirteen fetal centers across the world were surveyed. Results from all participating centers were recorded, analyzed, and presented as ratios. Questions on the survey were related to experience of the physician, preferred methods of transfusion, fetal surveillance, and timing of delivery.

RESULTS

Differences amongst centers were as follows: 54% of the centers performed transfusions in operating room, the remaining did them in a clinic room or close to the operating room; 31% did not use maternal anesthesia, 31% used oral or intravenous sedation and 38% used a combination of local with oral or intravenous sedation. The similarities include: 84% performed intravenous transfusions, while 2 centers reported intraperitoneal and intracardiac transfusions were performed for very early cases; 85% of centers performed the last transfusion at 34-35 weeks and 77% electively delivered their patients at 37 weeks.

CONCLUSION

Method of transfusion and delivery timing was similar in most centers; however, differences were seen in location of procedure, anesthetic coverage, and surveillance. Further assessment is needed to determine if these differences in practice have any potential neonatal effects.

Perinatal outcomes and central nervous system abnormalities following intrauterine fetal transfusion: 17 years' experience in a tertiary center

BACKGROUND

This study aimed to describe the perinatal outcome and central nervous system (CNS) anomalies in fetuses undergoing red blood cell (RBC) intrauterine transfusion (IUT).

METHODS AND MATERIALS

This was an observational single-cohort study carried out at Vall d'Hebron University Hospital in Barcelona, Spain, between 2002 and 2018 in women undergoing RBC IUT for suspected fetal anemia. Primary outcomes were adverse perinatal outcome (intrauterine or neonatal death and termination of pregnancy [TOP]), prenatal or postnatal CNS anomalies, and significant neurological impairment.

RESULTS

A total of 145 RBC transfusions were performed in 68 pregnancies of 60 women. The median gestational age for the first transfusion was 26 weeks (range, 18-32). Twenty-two (32%) fetuses were hydropic at the first transfusion. Fifty-eight pregnancies (85.3%) resulted in live births and 10 (14.7%) in adverse perinatal outcomes. Adverse perinatal outcomes were associated with hydrops (odds ratio [OR], 6.69; 95% confidence interval [CI], 1.53-29.23; P = .012) and gestational age at first transfusion (OR, 0.69; 95% CI, 0.54-0.89; P = .04). Four (5.9%) cases of cerebellar hemorrhage were diagnosed prenatally. In 14 (35%) of the 41 neonates undergoing brain ultrasound and/or magnetic resonance imaging (MRI) abnormalities were reported. The median follow-up was 6.5 years (range, 3 months to 19 years). Significant neurological impairment was reported in two cases (4.2%).

CONCLUSION

In fetuses undergoing intrauterine RBC transfusion, the survival rate is high, particularly in the absence of hydrops and if the gestational age at first transfusion is above 22 weeks. Significant neurological impairment is uncommon, despite the fact that postnatal CNS anomalies at ultrasound or MRI are frequent.

An Overview of Contemporary Outcomes in Fetal Cardiac Intervention: A Case for High-Volume Superspecialization?

Fetal cardiac interventions (FCI) offer the opportunity to rescue a fetus at risk of intrauterine death, or more ambitiously to alter disease progression. Most of these fetuses require multiple additional postnatal procedures, and it is difficult to disentangle the effect of the fetal procedure from that of the postnatal management sequence. The true clinical impact of FCI may only be discernible in large-volume institutions that can commit to a standardized postnatal approach and have sufficient case volume to overcome their FCI learning curve.

The near disappearance of fetal hydrops in relation to current state-of-the-art management of red cell alloimmunization

Objective

In this study, we aim to evaluate trends in the condition of fetuses and neonates with hemolytic disease at the time of first intrauterine transfusion (IUT) and at birth, in relation to routine first‐trimester antibody screening, referral guidelines, and centralization of fetal therapy.

Method

We conducted a 30‐year cohort study including all women and fetuses treated with IUT for red cell alloimmunization at the Dutch national referral center for fetal therapy.

Results

Six hundred forty‐five fetuses received 1852 transfusions between 1 January 1987 and 31 December 2016. After the introduction of routine first‐trimester antibody screening, the hydrops rate declined from 39% to 15% (OR 0.284, 95% CI, 0.19‐0.42, P < 0.001). In the last time cohort, only one fetus presented with severe hydrops (OR 0.482, 95% CI, 0.38‐0.62, P < 0.001). Infants are born less often <32 weeks (OR 0.572, 95% CI, 0.39‐0.83, P = 0.004) and with higher neonatal hemoglobin (P < 0.001). Neonatal hemoglobin was positively independently associated with gestational age at birth, fetal hemoglobin, and additional intraperitoneal transfusion at last IUT.

Conclusion

Severe alloimmune hydrops, a formerly often lethal condition, has practically disappeared, most likely as a result of the introduction of routine early alloantibody screening, use of national guidelines, and pooling of expertise in national reference laboratories and a referral center for fetal therapy.

What's already known about this topic?

Severe alloimmune hydrops is associated with impaired outcome on both the short term and the long term.

What does this study add?

With routine early alloantibody screening, national guidelines, and pooling of expertise in national reference laboratories and a referral center for fetal therapy, severe alloimmune hydrops has almost disappeared.

Survival of hydrops cases no longer differs from hemolytic disease of the fetus and newborn cases without hydrops.

Children treated with intrauterine transfusions are now in better condition at birth.

Complications of intrauterine intravascular blood transfusion: lessons learned after 1678 procedures

OBJECTIVE

Maternal alloimmunization to fetal red-blood-cell antigens is a major cause of fetal anemia, which can lead to hydrops and perinatal death if untreated. The cornerstone of management during pregnancy is intrauterine intravascular blood transfusion (IUT). Although this procedure is considered relatively safe, complications continue to occur. The aim of this study was to evaluate rates of procedure-related complications and perinatal loss following IUT, and their change over time, in order to identify factors leading to improved outcome.

METHODS

This was a retrospective analysis of all IUTs for red-cell alloimmunization performed at the national referral center for fetal therapy in The Netherlands, from 1988 to 2015. Differences in complication rates and their associations with alterations in transfusion technique after 2001 were assessed.

RESULTS

Between 1988 and 2015, 1678 IUTs were performed in 589 fetuses. For IUTs performed in 2001 and onwards, there was significant improvement in survival (88.6% vs 97.0%, P < 0.001) and a decline in procedure-related complications per fetus (9.8% vs 3.3%, P = 0.001) and per procedure (3.4% vs 1.2%, P = 0.003) compared with those performed before 2001. Procedure-related perinatal loss declined from 4.7% to 1.8% per fetus (P = 0.053). Beneficial changes in transfusion technique were routine use of fetal paralysis, increased use of intrahepatic transfusion and avoidance of arterial puncture.

CONCLUSIONS

IUT has become an increasingly safe procedure in recent years when performed by experienced hands. The chosen technique should be fine-tuned according to the patient's individual situation. The declining complication rates are most likely related to center volume: this rare procedure is best performed in experienced fetal therapy centers. © 2016 Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Fetal Treatment 2017: The Evolution of Fetal Therapy Centers - A Joint Opinion from the International Fetal Medicine and Surgical Society (IFMSS) and the North American Fetal Therapy Network (NAFTNet)

More than 3 decades ago, a small group of physicians and other practitioners active in what they called "fetal treatment" authored an opinion piece outlining the current status and future challenges anticipated in the field. Many advances in maternal, neonatal, and perinatal care and diagnostic and therapeutic modalities have been made in the intervening years, yet a thoughtful reassessment of the basic tenets put forth in 1982 has not been published. The present effort will aim to provide a framework for contemporary redefinition of the field of fetal treatment, with a brief discussion of the necessary minimum expertise and systems base for the provision of different types of interventions for both the mother and fetus. Our goal will be to present an opinion that encourages the advancement of thoughtful practice, ensuring that current and future patients have realistic access to centers with a range of fetal therapies with appropriate expertise, experience, and subspecialty and institutional support while remaining focused on excellence in care, collaborative scientific discovery, and maternal autonomy and safety.

Balancing Patient Access to Fetoscopic Laser Photocoagulation for Twin-to-Twin Transfusion Syndrome With Maintaining Procedural Competence: Are Collaborative Services Part of the Solution?

The benefits of fetoscopic laser photocoagulation (FLP) for treatment of twin-to-twin transfusion syndrome (TTTS) have been recognized for over a decade, yet access to FLP remains limited in many settings. This means at a population level, the potential benefits of FLP for TTTS are far from being fully realized. In part, this is because there are many centers where the case volume is relatively low. This creates an inevitable tension; on one hand, wanting FLP to be readily accessible to all women who may need it, yet on the other, needing to ensure that a high degree of procedural competence is maintained. Some of the solutions to these apparently competing priorities may be found in novel training solutions to achieve, and maintain, procedural proficiency, and with the increased utilization of 'competence based' assessment and credentialing frameworks. We suggest an under-utilized approach is the development of collaborative surgical services, where pooling of personnel and resources can improve timely access to surgery, improve standardized assessment and management of TTTS, minimize the impact of the surgical learning curve, and facilitate audit, education, and research. When deciding which centers should offer laser for TTTS and how we decide, we propose some solutions from a collaborative model.

Perinatal survival and procedure-related complications after intrauterine transfusion for red cell alloimmunization

OBJECTIVES

To study the perinatal survival and procedure-related (PR)complications after intrauterine transfusions in red cell alloimmunization.

METHODS

Prospective data of 102 women with Rh-alloimmunized pregnancy undergoing intrauterine intravascular transfusion for fetal anemia, from January 2011 to October 2014 were analyzed. Main outcome measures were perinatal survival and procedure-related (PR) complications.

RESULTS

A total of 303 intrauterine transfusions were performed in 102 women. Of 102 fetuses, 22 were hydropic at first transfusion. The mean period of gestation and hematocrit at first transfusion was 26.9 ± 3.3 weeks (range 19.7-33.8 weeks) and 17 ± 7.82 % (range 5.7-30 %), respectively. Average number of transfusions was 2.97 (range 1-7) per patient. Overall survival was 93 % and mean period of gestation at delivery was 34.5 ± 1.94 (range 28.3-37.4) weeks. Mean hematocrit at delivery was 36.9 ± 8.77 % (range 10-66 %). Fetal death occurred in four cases (3PR), neonatal death occurred in three cases (2PR). Emergency cesarean delivery after transfusion was performed in four pregnancies. The total PR complication rate was 2.97 %, resulting in overall PR loss in 1.65 % per procedure.

CONCLUSION

Our results compare favorably with other studies published in the literature. Intravascular transfusion is a safe procedure improving perinatal survival in fetuses with anemia due to Rh-alloimmunization.

Intrauterine blood transfusion: current indications and associated risks

Fetal anemia is a serious complication in pregnancy and associated with perinatal mortality and morbidity. During 25 years of worldwide experience with intravascular intrauterine blood transfusion, a variety of indications have been described. Intrauterine transfusion (IUT) treatment is considered most successful for fetal anemia due to red cell alloimmunization. Moreover, the use of this procedure has also been reported in pregnancies with parvovirus B19 infection, fetomaternal hemorrhage and placental chorioangiomas, for example. This review focuses on the current indications of intrauterine blood transfusions. In addition, we describe the potential complications of IUT treatment.

Learning curve for fetoscopic laser surgery using cumulative sum analysis

OBJECTIVE

To identify a learning curve and monitor operator performance for fetoscopic laser surgery for twin-to-twin transfusion syndrome using cumulative sum analysis.

DESIGN

Retrospective cohort study.

SETTING

National tertiary referral center for invasive fetal therapy.

POPULATION

A total of 340 consecutive monochorionic pregnancies with twin-to-twin transfusion syndrome treated with fetoscopic laser coagulation between August 2000 and December 2010.

METHODS

A learning curve was generated using learning curve cumulative sum analysis and cumulative sum methodology to assess changes in double survival across the case sequence. Laser surgery was initially performed by two operators, joined by a third and fourth operator after 1 and 2 years, respectively.

MAIN OUTCOME MEASURES

Individual operator performance, double perinatal survival at 4 weeks.

RESULTS

Overall survival of both twins occurred in 59% (201/340), median gestational age at birth was 32.0 weeks. Cumulative sum graphs showed that level of competence for double survival for the operators was reached after 26, 25, 26, and 35 procedures, respectively. Two operators kept their competence level and continued to improve after completing the initial learning process; two others went out of control at one point in time, according to the cumulative sum boundaries. A difference in learning effect was associated with number of procedures performed annually and previous experience with other ultrasound-guided invasive procedures.

CONCLUSIONS

This study shows that all operators reached a level of competence after at least 25 fetoscopic laser procedures and confirms the value of using the cumulative sum method both for learning curve assessment and for ongoing quality control.